Resistance Heating Element For a Hair Styling Device and a Hair Styling Device Equipped With Said Resistance Heating Element

ABSTRACT

Resistance heating element  1  for a hair styling device comprises a resistance heating wire arrangement held by a support body  2 , and a layer  4  which covers and electrically insulates the heating wire. The resistance heating wire arrangement has at least one heating wire  3 . The support body  2  is formed solely by a shape-stable hollow body consisting of an electrically insulating and heat resistant flexible material, and the outside of the resistance heating element  1  is formed by a layer covering the heating wire  3.

CROSS REFERENCE APPLICATIONS

This application is a national stage application of PCT application no.PCT/EP2007/050469 filed on Jan. 18, 2007 and claiming priority fromGerman application 20 2006 000 670.2 filed on Jan. 18, 2006.

BACKGROUND

The invention relates to a resistance heating element for a hair stylingdevice with a resistance heating wire arrangement having at least oneheating wire held by a support body, and a layer covering andelectrically insulating the one heating wire.

Hair styling devices, such as crimpers or curling irons, have hairstyling tools with which hair. Crimpers have hair styling platesarranged on one arm. Curling irons have a heated rod to wind the hairaround to form a curl. In all hair styling devices, heat is needed tostyle the hair. Therefore, the hair styling tools the need to be heated.Other than hair styling devices which use a hot air flow to provideheat, hair styling devices can have one or more resistance heatingelements integrated in the hair styling tool. The resistance heatingelements can be so-called PTC heating elements or a resistance heatingwire. PTC heating elements are so-called flat heating elements, whichare arranged in an aluminum envelope. The aluminum envelope surroundingthe actual heating element distributes the heat over the requiredsurface and transports the heat from the heating element to the insideof the hair styling tool. Resistance heating elements with a heatingwire are used in similar way. Such heating elements are typicallyintegrated in an aluminum envelope as heating cartridges or tubularheating bodies to distribute the generated heat and transport it to theinside of the heated surface or surfaces of the hair styling tool.

In hair styling devices with resistance heating elements a certain timeis required for the heat from the heating element to be transferred tothe surface of the hair styling tool. This is due to the aluminumenvelope needed to transfer the heat from the heating element to thehair styling tool also having to be heated. Due to the heated mass atoperating temperature, the hair styling tool also cools down relativelyslowly after being turned off. The heat transporting and distributingenvelope is made of aluminum, both because of the good thermalconduction properties and the relatively low specific weight ofaluminum. Finally, the hair styling tool and thus the entire hairstyling device should be as light as possible.

A curling rod with an electric heating is disclosed in EP 0 218 797 A2.A foil heating element is provided as the resistance heating element ofthis curling rod. The resistance heating foil is in direct contact withthe inside of the tube of the curling rod described in this document. Aslotted tubular spring element is used to attach the heating foil. Theoutside of the foil heating lies under pretension against the inside ofthe tube of the curling rod due to the spring element. This arrangementis required to carry away the heat generated by the resistance heatingwire of the heating foil, otherwise there is a risk of destroying theheating foil. The heating foil itself is a flexible, sheet likecomponent, which is placed against the inside of the tube of the curlingrod during the assembly process, before the desired surface pressure isapplied by the spring element. Therefore, the assembly of such aresistance heating foil needs to be done with special care if it is tobe inserted into a tube of a hair styling tool.

Starting from the above discussed prior art, the basic problem of theinvention is to modify the aforementioned resistance heating element sothat, an appliance, especially a hair styling appliance, with one ormore of these resistance heating elements has a faster heating andcooling response time, and it can be easily assembled.

The foregoing example of the related art and limitations relatedtherewith are intended to be illustrative and not exclusive. Otherlimitations of the related art will become apparent to those of skill inthe art upon a reading of the specification and a study of the drawings.

SUMMARY

The following embodiments and aspects thereof are described andillustrated in conjunction with systems, tool and methods which aremeant to be exemplary and illustrative, not limiting in scope. Invarious embodiments, one or more of the above described problems havebeen reduced or eliminated, while other embodiments are directed toother improvements.

This problem is solved according to the invention by a resistanceheating element where the support body is formed by a shape-stablehollow body consisting of an electrically insulating and heat resistantflexible material, and the outside of the resistance heating element isformed by a layer covering the heating wire.

The resistance heating element has material electrically insulating onlythe heating wires. Therefore, the support body holding the heating wiresis formed from such a material. Advisedly, this material is one with amineral base, in the disclosed embodiment mica is used as the basematerial. This resistance heating element has no metal lining. The layercovering and electrically insulating the heating wire, also typicallyconsisting of such a material, can additionally be coated on the outsideby one or more polyimide foil layers if an improved electricalinsulation is needed between the resistance heating wire and the hairstyling tool being heated. A polyimide layer can be provided in the formof a thin coating or a foil deposition.

The actual support for this resistance heating element is formed by theheated tool itself, for example, the hair styling tool. If this is acurling iron, the resistance heating element is integrated into thetubular curling iron and its outside directly borders on the inside ofthe curling iron. The two elements—resistance heating element andcurling iron—can be joined together by gluing. Thus, this resistanceheating element is ultimately borne by the tool being heated. Thegenerally flexible properties of an electrically insulating materialformed on a mineral base, especially a mica base, allow the resistanceheating element to easily be adapted to the inner contour of a hairstyling tool. Therefore, it is unnecessary for the resistance heatingelement to have a firmly defined outside contour, especially one whichis adapted to the heating element holder of the tool. Only thecircumference of the resistive heating element needs correspond to thecircumference of the inner envelope surface of the hair styling tool.The arrangement of the resistance heating element and especially theresistance heating wire in immediate proximity to the surface of thehair styling tool being heated has the benefit that the heat is producedwhere it is actually needed. Therefore, very little to no heatdistributing or heat transporting shapes are required. This results in avery quick response time, so that the desired heat is available on thehair styling tool almost immediately after turning on the resistanceheating element. The slight heated mass, which is basically only themass comprised of the heated surface of the hair styling tool, alsocools down the tool quickly. The quicker response time of the hairstyling tool in terms of its warm-up and cool-down brings benefits bothin the handling of the hair styling device and in energy consumption.

The support body for the at least one heating wire of the resistanceheating wire arrangement is stable in shape. The support body can havevarious shapes. For example, it can be configured as a piece ofcylindrical pipe. This has the benefit that the support body or theresistance heating element can be a support for other components at thesame time. The components are then placed in a definite arrangement tothe support body and particularly its resistance heating wirearrangement. This involves the arranging of a thermal fuse, whichremains in the same arrangement for a temperature detection due to theshape-stable properties of the support body, even after the resistanceheating element has been placed on a tool, such as in the tube of acurling iron.

The heating wire can be arranged in various ways on the support body. Inparticular, when the support body is a ring body, such as an annularcylinder segment, one will wind the heating wire about the cylindricalsupport body.

Making the support body a hollow body also has the benefit that therequired leads for the heating wire and possibly other elements, such asa thermal fuse and/or a sensor element, can be arranged on the interior.Due to the interior contacts, the entire outside of the resistanceheating element can be used as a heating surface.

In addition to the exemplary aspects and embodiments described above,further aspects and embodiments will become apparent by reference to theaccompanying drawings forming a part of this specification wherein likereference characters designate corresponding parts in the several views.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematized perspective view of a resistance heating elementfor a curling iron as a hair styling device.

FIG. 2 is a schematized longitudinal section through the resistanceheating element of FIG. 1, integrated in a curling iron.

FIG. 3 is an enlarged cutout from FIG. 2.

Before explaining the disclosed embodiment of the present invention indetail, it is to be understood that the invention is not limited in itsapplication to the details of the particular arrangement shown, sincethe invention is capable of other embodiments. Exemplary embodiments areillustrated in referenced figures of the drawings. It is intended thatthe embodiments and figures disclosed herein are to be consideredillustrative rather than limiting. Also, the terminology used herein isfor the purpose of description and not of limitation.

DETAILED DESCRIPTION OF THE DRAWINGS

A resistance heating element 1 comprises a support body 2, on which aresistance heating wire 3 is wound in several turns. The resistanceheating wire 3 wound around the support body 2 in several turnsconstitutes the resistance heating wire arrangement in the depictedsample embodiment. The heating wire 3 is covered on the outside by aheat distributing and electrically insulating layer 4 in the manner ofan envelope. The turns of the heating wire 3 on the support body 2 canbe seen through the cut-outs in the layer 4. The support body 2 and thelayer 4 forming the outer envelope are a material made from a mica basein the depicted embodiment, such as is known by the name micanite. Thesupport body 2 in the depicted embodiment consists of a thin micanitesheet. The support body 2 is formed into the annular cylindrical shaperecognizable in FIG. 1 before the heating wire 3 is wound on the outsideof the support body 2. Therefore, the support body 2 has a shapestability consistent with the requirements.

The leads for making contact with the heating wire 3 are located insidethe support body 2. For this purpose, the two ends of the resistanceheating wire 3 are each fed through an opening into the interior of thesupport body 2. One of the two openings is indicated by 5 in FIG. 1,through which one end of the resistance heating wire 3 is fed throughthe support body 2.

On the outside of the resistance heating element 1 there is a standardtemperature sensor 6. The two lead pins 7, 7′ of the temperature sensor6 reach through the layer 4 and the support body 2 and are likewise fedinto the interior of the support body 2. Thus, the temperature sensor 6is located immediately on the outside of the resistance heating element1. When the resistance heating element 1 is used to heat a tubularobject, such as a curling iron, it lies against the inside of the tool.Therefore, it is not necessary to provide and electrically connect anadditional temperature sensor in the resistance heating element 1 as aself-standing unit independent of the heating element 1. The resistanceheating element itself can serve as support for the temperature sensor 6due to the direct arrangement of the outside of the resistance heatingelement 1 on the inside of the tool being heated. The contact pins 7, 7′of the temperature sensor 6 are connected to electrical plug contacts 8,8′. The plug contacts 8, 8′ protrude from the support body 2 in thelengthwise direction and make contact with a complementary mating plugto hook up the temperature sensor 6. In the depicted embodiment, theplug contacts 8, 8′ are fastened on the inner lateral surface 9 of thesupport body 2.

A holder 10 for a standard thermal fuse 11 is riveted on the innerlateral surface 9 of the support body 2. The thermal fuse 11 is set in aglass silicone sleeve 12 and protects against overheating

The arrangement of the electrical contacting of the heating wire 3,which lies inside the support body 2, can be seen in FIG. 2. Theresistance heating element 1 is inserted in a tube 13 of an otherwisenot further represented curling or hairdressing iron, while only asegment of the curling iron tube 13 being heated is shown in FIG. 2. Toassure the necessary electrical insulation between the resistanceheating element 1 and the tube 13, three layers of a polyimide foil areplaced on the outside of the resistance heating element 1 in thedepicted embodiment. This is somewhat longer in its lengthwise dimensionthan the length of the support body 2.

The enlarged cutout from FIG. 2, presented in FIG. 3, shows thearrangement of the heating wire 3 provided in immediate proximity to theinner lateral surface 14 of the tube 13. The support body 2 and thelayer 4 serving as the outer envelope are shown in FIG. 3 as a combinedbody since these are identical in material. Thus, the layer 4 whichforms the envelope is also a shaped piece of micanite. The shapedmicanite piece strengthens the shape stability of the resistance heatingelement 1. The separating surface between the support body 2 and thelayer 4 is shown by broken line in this figure. The heating wires 3 havebeen wound on the original outer side of the support body 2 and areembedded in electrically insulating manner in this body formed fromsupport body 2 and layer 4 due to the enveloping by the layer 4. Theheating wire 3 wound around the support body 2 is pressed into thesupport body 2 and into the layer 4 forming the outer envelope.

The resistance heating wire 3 in the depicted embodiment is separatedfrom the inner lateral surface 14 of the tube being heated solely by thelayer 4 forming the outer envelope of the resistance heating element andthe layers of the polyimide foil 15. Therefore, the path of the heatgenerated by the heating wire 3 to the outer envelope surface 16 of thetube 13, against which the hair lies for the hair styling, is reduced toa necessary minimum. This figure also illustrates that the heating wire3 only needs to heat the tube 13 serving as the hair styling tool, toprovide the desired heat on this outer lateral surface 16 to carry outthe hair styling process. Thus, the tube 13 serves not only as an outerrigid support body for the resistance heating element 1, but also as afurther heat distributor. The resistance heating element 1 does not needto extend for the entire length of the tube 13 of the curling iron dueto the heat distributing properties of the tube 13. The resistanceheating element 1 lies with its outside peripherally against the insideof the tube 13 because of its annular cylindrical structure, so that thetube 13 has a uniform heat distribution over the outside circumference.

While a number of exemplary aspects and embodiments have been discussedabove, those of skill in the art will recognize certain modifications,permutations, additions and sub-combinations therefore. It is thereforeintended that the following appended claims hereinafter introduced areinterpreted to include all such modifications, permutations, additionsand sub-combinations are within their true sprit and scope. Eachapparatus embodiment described herein has numerous equivalents.

LIST OF REFERENCE NUMBERS

-   1 Resistance heating element-   2 Support body-   3 Resistance heating wire-   4 Layer-   5 Opening-   6 Temperature sensor-   7, 7′ Connection pins-   8, 8′ Plug contacts-   9 Inner lateral surface of the support body-   10 Holder-   11 Thermal fuse-   12 Glass silicone sleeve-   13 Tube-   14 Inner lateral surface of the tube-   15 Polyimide foil-   16 Outer lateral surface of the tube

1-10. (canceled)
 11. A resistance heating element for a hair stylingdevice comprising: at least one heating wire held by a support body anda layer which covers and electrically insulates the at least one heatingwire; wherein the support body is formed from a shape-stable hollow bodyconsisting of an electrically insulating and heat resistant flexiblematerial; and an outer surface of the resistance heating element isformed by the layer covering the heating wire.
 12. The resistanceheating element of claim 11, wherein the support body is an annularbody, especially an annular cylinder.
 13. The resistance heating elementas claimed in claim 11 or 12, wherein the electrically insulating andheat resistant material of the support body and the layer coveringheating wire is a mineral based material.
 14. The resistance heatingelement as claimed in claim 11 or 12, wherein electrical leads formaking contact with the heating wire are arranged on an interior of thesupport body.
 15. The resistance heating element as claimed in claim 13,wherein electrical leads for making contact with the heating wire arearranged on an interior of the support body.
 16. The resistance heatingelement as claimed in claim 11 or 12, wherein the resistance heatingelement is associated with a thermal fuse arranged on an interior of thesupport body.
 17. The resistance heating element as claimed in claim 13,wherein the resistance heating element is associated with a thermal fusearranged on an interior of the support body.
 18. The resistance heatingelement as claimed in claim 11 or 12, wherein a temperature sensor isarranged on the outer surface of the resistance heating element withelectrical connection contacts of the temperature sensor lying insidethe support body.
 19. The resistance heating as claimed in claim 11 or12, wherein the outer surface of the resistance heating element isarranged in almost direct contact with a tubular tool being heated, withthe interpositioning of at least one foil layer serving as electricalinsulation.
 20. The resistance heating as claimed in claims 13, whereinthe outer surface of the resistance heating element is arranged insubstantially direct contact with a tubular tool being heated, with theinterpositioning of at least one foil layer serving as electricalinsulation.
 21. The resistance heating as claimed in claims 14, whereinthe outer surface of the resistance heating element is arranged insubstantially direct contact with a tubular tool being heated, with theinterpositioning of at least one foil layer serving as electricalinsulation.
 22. The resistance heating element as claimed in claim 21,wherein one or more layers of a polyimide foil are arranged between theouter surface of the resistance heating element and the surface of thetool being heated, for the electrical insulation of the resistanceheating element relative to the tool being heated.
 23. The resistanceheating as claimed in claim 11 or 12 further comprising: a hair stylingappliance with a heated hair styling tool wherein the hair styling toolcomprises a tube having an outer lateral surface for use in a hairstyling process; and wherein one or more resistance heating elements arearranged in the tube.
 24. The resistance heating element of claim 23,wherein the hair styling appliance is a curling iron.